Implement NSAccessibilityScrollToVisibleAction on Mac

third_party/WebKit/Source/modules/accessibility/AXObject.cpp

Index: third_party/WebKit/Source/modules/accessibility/AXObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
index 3167659f49f35e6729150c58318bc73291de8ec4..ae6eb0da97d358fce9a1d0067561c5e55e9056f5 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
@@ -1516,7 +1516,7 @@ static int computeBestScrollOffset(int currentScrollOffset, int subfocusMin, int
 void AXObject::scrollToMakeVisibleWithSubFocus(const IntRect& subfocus) const
 {
     // Search up the parent chain until we find the first one that's scrollable.
-    AXObject* scrollParent = parentObject();
+    const AXObject* scrollParent = this;

[Elly Fong-Jones, 2016/09/26 16:25:39]

what's up with this?

[dmazzoni, 2016/09/26 18:00:40]

It's part of the change.

Previously we didn't have a use case for calling
scrollToMakeVisibleWithSubFocus when the object itself
is the one that needs to scroll. Previously we'd call
it on an object like a heading or a button and it'd
search up for the nearest scrollable container.

In this case we want to call it on the document, which
is scrollable - but we want to tell it to scroll to a
certain bounding box rect (subfocus).

     ScrollableArea* scrollableArea = 0;
     while (scrollParent) {
         scrollableArea = scrollParent->getScrollableAreaIfScrollable();